Some of the world’s most influential leaders in politics and business are meeting at the World Economic Forum in Davos, Switzerland.

DAVOS, Switzerland – Each year, the Russian presence at the World Economic Forum seems to grow, with government and business delegations courting investment, as well as the press.

And each year, Bill Browder of Hermitage Capital, comes to Davos to, among other things, seek justice for his lawyer Sergei Magnitsky, who he claims was killed in a Russian prison while investigating tax fraud.

Browder, who with the late Edmund Safra founded founded the investment firm which specializes in Russian markets, does not mince words.

"The Russian government plays this silly game,” Browder said. “They wash up, dress up, come to Davos and pretend they are normal, Western business people looking to attract investment, and in my opinion, they shouldn't be allowed to behave like criminals at home and then dine at our tables with white tablecloths when they come to Davos."

Browder claims Magnitsky, who was 37, when he died in 2007, was tortured, and ultimately denied medical care in jail. Browder, who had been the biggest foreign portfolio investor in Russia, claims $230 million he paid in taxes to the Russian government was stolen by people with ties to the government. Magnitsky had been looking for the money.

The Russians are defiant about the case, and have not convicted anyone.

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But Browder has succeeded in lobbying Washington to pass legislation that places asset freezes and visa bans on the 60-some people he says were in some way involved or complicit in Magnitsky's death. The law, which carries various sanctions for human rights abusers, is believed to have prompted Russia to ban adoptions of Russian orphans by Americans in retaliation, according to reports.

The Magnitsky human rights law continues to rankle the Russians. Foreign Minister Sergei Lavrov just this week said, "the situation was cynically used in order to punish Russia."

There has been similar outrage in the U.S. about the adoption ban.

"It is kind of like when Saddam Hussein was taking women and children and using them as human shields in military bunkers and so on," Browder said. "He [Russian President Vladimir Putin] has grabbed a bunch of the most vulnerable members of society, disabled orphans, and used them as human shields in the hopes that people will think he is so crazy that no one will provoke him to do more than he has already done."

A few months ago, a whistleblower who was helping Browder trace some of the tax money he claims was stolen dropped dead in London and the cause of his death is still not clear. Browder says 44-year-old Alexander Perepilichny had been in otherwise good health.

Browder has been fighting the Russians for some time. He had been an active anti-corruption crusader when he was expelled from Russia in 2005. Moscow had called him a threat to national security.

Even now they are going after him, for alleged tax evasion. But, Browder claims, they are not going after Magnitsky's killers."The only prosecution they are doing right now is a prosecution that starts Monday, which is the posthumous prosecution of Magnitsky," Browder said, "and they are going to prosecute me in absenting as his co-conspirator."

Amy Kellogg currently serves as a Senior Foreign Affairs Correspondent based in the London bureau. She joined Fox News Channel (FNC) in 1999 as a Moscow-based correspondent. Follow her on Twitter: @kellogglondon